by Brien A. Seeley M.D.

Wildfires destroy ecosystems, entire towns, people’s homes and businesses. Their flames and smoke can kill as many as 339,000 people annually across the globe. But the biggest reason we must end wildfires is because of their effect on the climate crisis. Calculations show that, due to the cumulative effects of global wildfires, an astonishing 56.6 gigatonnes (Gt) of CO2 per year could be added to our planet’s atmosphere. That 56.6 GtCO2 dwarfs the roughly 38 GtCO2 per year emitted by the entire global use of fossil fuels. How could this be?

Up to now, the global CO2 due to fires has been largely overlooked by mainstream climate science, which considered fires to be an immutable natural phenomenon from which rapid regrowth was expected to provide spontaneous recovery. Global wildfire smoke emissions of about 6 GtCO2 per year were considered a relatively small concern. However, in March 2023, research by the Sustainable Aviation Foundation found that wildfires, due to the cumulating losses of CO2 sequestration in global burned areas of vegetation, are a potentially huge source of greenhouse gases. Recent more accurate data for global burned area (Chen et al) and net ecosystem exchange (NEE, Zhuravlev et al), when paired with realistic regrowth periods to quantify this cumulating loss of sequestration, reveal it to be over 50 GtCO2 per year and thereby to have a major role in the worsening climate crisis.

What’s more, as the climate crisis worsens, so do wildfires. According to the UN, in the last 30 years, climate change is estimated to have doubled the total forest area burned in the western United States. Add to this, the fact that a recent UN Environmental Programme predicts a 30% increase in extreme wildfires by 2050, and the urgency of ending wildfires becomes apparent. FIGURE 1 and 2, below, show that according to NOAA data, atmospheric CO2 is increasing more each decade and the size of the CO2 reduction by photosynthesis during successive annual growing seasons is clearly lessening each year. These are findings that fit with a massive and progressively increasing annual loss of CO2 capture due to burned vegetation.

FIGURE 1. (above) NOAA graph shows that the growing season’s drop in CO2 due to photosynthesis by plant growth is diminishing each year, as would be expected with a cumulating global loss of sequestration of CO2 due to burned vegetation.

FIGURE 2. This NOAA graph reveals that the rise in atmospheric CO2 per decade is substantially increasing. Wildfire damage could be a major cause of this increase.

Respected climate scientists have stated that their predictive models cannot fully explain why the years 2023 and 2024 were the hottest years on record. However, those models apparently have not included accounting for the huge amount of CO2 sequestration lost due to global burned areas and intentional deforestation. See FIGURES 3 and 7, below.

FIGURE 3. The solid blue line showing the lost capture of CO2 due to fires does not include losses due to intentional deforestation. The steep drop in lost capture of CO2 by ending wildfires, shown by the dashed green line, indicates a potential path that could rapidly curb the climate crisis.

FIGURES 4 and 5, below, show that ending ending wildfires globally could rapidly and substantially cut net atmospheric CO2 emissions enough to limit global temperature rise to the 1.5° C limit set by the Paris Climate Summit.

FIGURE 5. Length of the downward green arrows depict the calculated amount of CO2 avoided per year after wildfires are ended. These amounts appear to be sufficient to limit global warming to 1.5°C if we can end wildfires starting in 2030.

Recent symposia on how best to mitigate the climate crisis need to be informed about this promising prospect of ending wildfires.

Background

Each year, global wildfires burn huge areas of vegetation, destroying its photosynthetic capability. This prevents it from removing billions of tons of CO2 from thin air and turning it into the sugars, starch and cellulose that we recognize as food, wood, grasses, plants and shrubs. Burned vegetation typically recovers from this loss of photosynthetic capacity over a number of years, depending on which type of vegetation was burned.

The rate of regrowth (‘regreening’) after a fire takes some years to restore 100% of the lost photosynthetic capacity and is crucial to how much CO2 capture is lost. With complete combustion and subsequent drought, regrowth can take several decades. Regrowth of a burned biome typically consists of three main phases. Initially, there is the period of microbial and insect respiration that consumes the dead detritus on the surface that burned. This releases substantial amounts of CO2 into the atmosphere. Next comes the period of growth during which ‘regreening’ occurs. This includes the sprouting of new small plants, which at first are mainly grasses or weeds, and which begin to restore some CO2 capture. Finally, after some years, there comes the much longer period of biomass restoration in which a succession of plant regrowth from grasses to shrubs to trees eventually can recreate the lost biomass.

Methods

The amounts of lost CO2 capture that were discovered by the research at the Sustainable Aviation Foundation were calculated by using recent reputable data for mean global burned area (BA) for the period of years 2000 to 2019 and the best yet values for net ecosystem exchange (NEE) of various types of land cover. Assuming 100% combustion, the product of these BA times NEE values generated an annual loss of CO2 capture for each land cover type. A linear recovery of that loss of CO2 capture was calculated for each land cover type using the following consensus estimates of 100% regrowth time: grassland 1 year, savannah/shrub 4 years, and forests 20 years. The ‘NEE calcs’ spreadsheet containing these calculations also enumerates the uncertainties and variables involved. Other sheets within that spreadsheet provide a matrix that details the projections of lost sequestration of CO2 by land cover type and the projected cost of mitigating wildfires.

Discussion

Decades of conferences, scientific papers, dire warnings and negotiations have obviously failed to produce the actions needed to meaningfully curb fossil fuel CO2 emissions. But what actions to mitigate the climate crisis have the greatest promise? The climate impact of wildfires is now found to be so large that its mitigation actually surpasses that of other recognized climate mitigation initiatives. Let’s compare two prime contenders.

Nobel Winner Al Gore’s June 16, 2025 TED Talk shouted the alarms and pointed out that the oil lobby now forsakes GHG reductions for instead the fatalistic and self-serving stance called “Climate Realism”, recommending adaptation rather than mass-scale mitigation. Gore’s response touted growth in EVs and solar/wind renewable energy as the foremost mitigations to cut fossil fuels. He declared a cost of $4.4T to finance the global transition to renewable energy and an optimistic reduction in emissions of 34% in 5 years. However, the actual global increase in new renewable energy in both 2023 and 2024 was about 0.5 terawatts per year, which, according to the conversion ratio that equates 1 terrawatt of new renewable energy as capable of replacing 2 gigatonnes of fossil CO2 emissions, means that we have only replaced 1 GtCO2 of fossil fuel use in each of those years. The total cost to create and install the 18 terawatts of new renewable energy that would be necessary to totally replace the roughly 36 GtCo2 of annual global fossil fuel emissions, including the costs of required grid, battery storage and other infrastructure comes to about $25T, and would likely take at least 15 years to achieve. Assuming Al Gore’s optimistic timeline, implementing 18 terawatts of new renewable energy over a 15-year period would mean adding an average of 1.2 terawatts each year. That 1.2 terawatts would replace 2.4 GtCO2 per year of fossil fuel use.

Accordingly, the first-order average annual Net Economic Benefit (NEB) of Gore’s push for renewable energy, using the US EPA Social Cost of Carbon (SCC) figure of $190B per GtCO2 emitted, would be:

Annual NEB = 2.4 GtCO2/year x $190B/GtCO2) – ($25T/15 years) =

a negative $1.21T per year

Note that this NEB has a net expense, a cost of $1.21T per year cost and that replacing the full 36 GtCO2 annual emissions from fossil fuel with 18 terawatts of new renewable energy would not occur in year-one, but rather only after adding an average of 1.2 terawatts each year for 15 years.

By comparison, the Sustainable Aviation Foundation has projected that a global program of Autonomous Aerial Firefighting (AAF) could feasibly and affordably end global wildfires and thereby restore massive amounts of CO2 sequestration. In the first year of ending wildfires, 17.7 GtCO2 would be saved at an average annual AAF cost of $0.28T, producing a Net Economic Benefit of $3T in year-one and, with saving 25.8 GtCO2 in year-two, an NEB of $4.6T in year two. Over a 20-year period, the NEB return on investment of AAF rises to $7.5T per year. Comparing the amount of CO2 avoided in the first two years of mitigation shows renewable energy to save 4.8 GtCO2 and AAF to save 43.5 GtCO2.

These calculations make obvious the huge advantages that can be obtained by rapidly ending wildfires globally. And AAF appears to be the only feasible and affordable mitigation path to achieve that. The NEB for global AAF far surpasses that of any other climate mitigation initiative, as would the magnitude and rapidity of its forecast CO2 reductions. It can be argued that without AAF, that $7.5 trillion USD instead becomes untenable global losses and damages of $8.0 trillion USD per year, urging that we must end wildfires.

A crucial feature of AAF is its ubiquitous network of 3-acre airparks that provide high proximity and early arrival at any wildfire. See FIGURE 6, below

FIGURE 6. (above) Blanketing California with 120 three-acre airparks is enough to enable eTankers to reach any wildfire within 10 minutes of flight. Caltrans lists California as already having 242 public use airports, many of which could be modified to include a three-acre AAF airpark.

It must be noted that the 56 GtCO2 per year attributable to wildfires does not include an additional 9,2 GtCO2 per year attributable to intentional global deforestation, including its smoke. Unabated at that rate, with zero regrowth after 20 years, deforestation’s cumulated annual loss of CO2 capture would reach 184 GtCO2 and $35 trillion USD. See FIGURE 7, below.

FIGURE 7. (above) The enormous global costs of intentional deforestation.

From climate scientist John O’Brien, comes this additional caution about how timber harvesting affects climate change. He cites the common industry talking point that carbon stored in lumber products (chairs, homes, etc) is part of the solution to fighting climate change: “Ultimately it comes down to 80% of the carbon in a standing tree is lost [by timber harvesting] to the atmosphere; only about 20% makes it into a wood product that has an average lifetime of about 40-70 years.” In fact, timber harvesting itself is the largest emitter of CO2 of any natural or human-caused forest disturbance type.

Conclusions

The calculated annual loss of CO2 sequestration of, 56 GtCO2 per year, when cumulated over a 20 year period due to global wildfires, combined with the all-time hottest global temperatures recorded in 2023 and 2024 and the recent NOAA graphical evidence of a progressive loss of global CO2 capture during the growing season, all point to wildfires as a major driver of the climate crisis. The continued international stagnation in effectively reducing the global use of fossil fuels and the too-small incremental gains from other mitigations, makes the prospect of rapidly and meaningfully reducing CO2 by ending wildfires a mitigation that now merits urgent attention. In related work, Sustainable Aviation Foundation has projected that a global program of Autonomous Aerial Firefighting (AAF) could feasibly and affordably end global wildfires. See FIGURE 8, below. Together, these findings emphasize the urgency of the need and the momentous opportunity to end wildfires globally. That can be affordably achieved with AAF, Autonomous Aerial Firefighting. What is needed now is the collective will to prioritize AAF while continuing all of the other mitigations enumerated in Project Drawdown.